1. Field of the Invention
The present invention relates to a photoelectric coupling assembly for connecting an electrical circuit and an optical fiber and a method for manufacturing the photoelectric coupling assembly.
2. Description of the Background Arts
With the development of broadband communication systems, higher speeds and larger capacities are increasingly in demand for networked household electric appliances as well as for routers at network nodes. Consequently, the investigation and implementation of optical interconnections is on the rise. An optical interconnection is a connection arrangement contrived to carry out a photoelectric conversion at a boundary section (interface) between a signal processing section and a signal transmission section such that the broadband capacity of optical fiber technology can be utilized to accomplish high-speed, high-capacity transmissions. Japanese Laid-Open Patent Application Publication No. 2005-43622, for example, discloses a technique in which an electrical circuit and an optical fiber are coupled together at a photoelectric conversion section using a photoelectric coupling assembly that includes a photoelectric conversion element (a light-emitting element or a light-receiving element) and an optical fiber holding member.
FIG. 11 is a cross sectional view showing the assembled state of an optical fiber cable connected to a photoelectric coupling assembly in accordance with the disclosure of Japanese Laid-Open Patent Application Publication No. 2005-43622. The photoelectric coupling assembly 100 includes a molded article 104 having holding holes 102 each configured to mechanically hold an optical fiber 101 such that an optical input/output end surface 103 of each optical fiber 101 is exposed at a main surface. An electrical wiring pattern 105 is provided on the main surface and a side surface of the molded article 104 such that the portion of the electrical wiring pattern 105 on the main surface is connected to the portion of the electrical wiring pattern 105 on the side surface. A photo-semiconductor element 107 is provided in front of the optical fiber 101 with an insulating film 106 disposed there-between. The photo-semiconductor element 107 is connected to the electrical wiring pattern 105 with bumps 108. The same patent publication claims that the degree of freedom with which the photo-electric coupling assembly can be arranged is increased by having the kind of electrical wiring pattern just described. However, it is inherently difficult to form an electrical wiring pattern in a continuous manner on the surface of an object such that the wiring pattern is accurately positioned in three dimensions.